Only let your manner of life be worthy of the gospel of Christ, so that whether I come and see you or am absent, I may hear of you that you are standing firm in one spirit, with one mind striving side by side for the faith of the gospel, (Philippians 1:27, ESV)"Only let your manner of life be worthy of the gospel of Christ..." could be more literally translated as, "Only live as citizens of the gospel of Christ..." Saying it the other way is a great translation, especially for us because we don't see citizenship in the same light as these Philippian Christians would have.
A little history... In the city of Phillipi, all of its citizens had been granted Roman Citizenship. This was a great privilege because not everyone was granted the rights of citizenship. Phillipi had earned this special privilege because it had once been a Roman outpost. The city itself had been modeled after Rome, with the style of architecture and such. It is said that if one were to visit Phillipi, they would have felt like they were in Rome. If my memory serves me correctly, it had even held an unofficial title of "Little Rome."
Because of this, the people of Phillipi would have held in high regard the concept of citizenship. They would have wanted to live and act in a way that is worthy of Roman Citizenship. This sentiment is what Paul is drawing on as he encourages them to live a life worthy, not of Roman Citizenship, but of Gospel Citizenship. Thinking of all that Christ has done to bring us the good news, live a life worthy of that!
What a profound statement this actually is.
And how does he initially commend them to live a life that is worthy of this particular citizenship? It is all about unity. Whether Paul is present with them or apart from them and in a different location, they are to stand firm, side by side, for the sake of this same Gospel.
As we progress through the rest of chapter one and into chapter two, we will see this theme of unity creep into the remainder of the conversation. Just don't forget that the foundational thought is to live worthy of the Gospel of Jesus Christ.